Ceres: asteroid to dwarf planet

Status is a funny thing. When Pluto was relisted as a dwarf planet, it was definitely a demotion. For the former asteroid Ceres, however, it was a step up. What had been an unusually large asteroid has moved into a whole new league. This was a bit unfortunate for astrologers, as they had taken the four largest asteroids, all named for Classical goddesses, as a balancing-act for the male-dominated planets.

I suppose now Pluto and Ceres are in a separate league of their own, which might make sense, both having a chthonic aspect. And, the latest theory on the asteroid’s origin is that it originally came from the Kuiper Belt, a disc-shaped region of icy objects beyond Neptune.

While on the subject of status, Ceres very nearly missed becoming the fifth planet from the sun. One proposal before the International Astronomical Union during the kerfuffle over Pluto suggested that a planet be defined as:

“a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid-body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet”.

This proposal was not adopted, instead a modified version stating that a planet had to have “cleared the neighborhood around its orbit”, was adopted, probably to put Ceres out of contention. It is ironic, then, that Ceres was initially discovered it was assumed to be a planet. In answer to the question of what exactly Ceres is now; it has a double designation, according to the Minor Planet Center, classified as both a dwarf planet and an asteroid.

This asteroid has the peculiar honour of being discovered twice. First a Sicilian astronomer named Guiseppi Piazzi saw it in 1799, but he lost track of it. Then on New Year’s Eve in 1801 another astronomer named Franz Xavier Von Zach (a Hungarian) saw it in the region of Virgo.

Astronomical symbol for Ceres. From wikimedia commons.

For this reason, and because Ceres was the patron of Sicily, his choice of name was obvious. (Its original name was Ceres-Ferdinandea after the Bourbon king of the island, but the French were somewhat unpopular at the time, and there are rules about naming planets and such. Nor was he the only one; Herschel wanted the then new planet Uranus named after George III, which never took outside England.)

It was the astronomer Johann Elert Bode who first proposed that there must be a planet between Mars and Jupiter, because he felt that the Titus-Bode Law, which held that there was a regular pattern to the orbits of the planets, called for another planet there. He wasn’t to know that if there ever had been another planet there, it was in millions of pieces.

Ceres as photographed by Hubble and Dawn.

Ceres takes four and a half years to orbit the sun, and rotates on its axis in nine hours. It has been in the news lately because the icy asteroid/dwarf planet sent up plumes of water vapour in 2014, and now the first photos back from the Dawn explorer show bright white patches which may be large areas of ice. These possibilities of water, either frozen or vapour, are exciting to scientists still trying to figure out how life began on Earth. Fittingly, the water vapour was discovered by the Herschel telescope.

Ceres with cornucopia and scepter.

In astrology, it is mostly related to the principle of nurture, fittingly for a grain goddess and mother. Ceres (Demeter to the Greeks) in a person’s chart often indicates service and practicality. It is also related to labour – and perhaps could be the patron of labour unions, especially since Ceres staged the first sit-down strike after Pluto abducted her daughter, Proserpine.

As Philip Sedgwick pointed out, she only got her daughter back for half the year, thanks to a trick by Hades, but to take on the gods and win was very unusual – when Hera sided against Zeus during the Trojan War, he hung her from the heavens by her hair with anvils attached to her ankles.

The Roman goddess was originally a member of the Aventine or plebian triad, with the god Liber and his partner, Libera. Some have suggested that their temple on the Aventine hill in Rome, and the cult associated with it, were part of the plebs’ asserting themselves against the patricians and the Capitoline Triad, along with the dramatic performances and games associated with them.

Astrologers have assigned Ceres co-rulership of the sign Virgo, along with the asteroid Vesta.